In January 1858, Mathew Brady opened a studio on Pennsylvania Avenue, N.W., at the center of Washington's business district, halfway between the White House and the Capitol. Alexander Gardner ran the new business while Brady continued to bring in customers and promote the studio. A practical businessman and progressive photographer, Gardner introduced Brady to the new carte-de-visite camera, which made it easy to produce images in large quantities. Families collected these small, inexpensive portraits in leather-bound albums; to their carte portraits of family and friends, they added portraits of famous men and women, many also photographed by Brady.

In 1861, when the Civil War began, Brady sent his Washington photographers out into the field, in part to acquire portraits of military leaders. Later, both Brady and Gardner claimed credit for photographing the war in all its phases. In fact, countless photographers followed the army, though most were only interested in the profits that came from making portraits for soldiers to send back home.

Brady supported his war work by selling negatives of war images and celebrity cartes de visite to the E. & H. T. Anthony Company in exchange for cameras and supplies. For many years, the Anthonys published and sold Brady's portraits and war views, in series such as "Incidents of the War," and "Brady's Album Gallery." Brady also continued to profit from these historic photographs, selling another set of negatives to the United States government in 1875, and keeping a collection of portraits on view in his gallery until the end of his life. At the turn of the century, the Anthony company sold Brady's negatives to Frederick Hill Meserve, a Lincoln expert and amateur historian. In 1981, when Meserve's family finally put his collection up for sale, the National Portrait Gallery acquired more than five thousand negatives for the Smithsonian Institution.